# n = 1
# def func(a,b) :
#     global
#     print(n)
def multiply(n):
    result = n*(n-1)
    return result
def jiecheng(n) :
    if n == 0 or n == 1 :
        result  = 1
    elif n > 1 :
        while True :

            if n == 1:  
                break
            else :
                result  = multiply(n)
            n -= 1
    return result
print(jiecheng(3))

            